Production of emulsions



March 15, 1938. A MULLER 2,111,402

PRODUCTION OF EMULSIONS I Filed Sept. 27, 1954 MTEZ SOLQT/OQ Qf SOLUTION lA/SOLUBLEI H PROTfC'T/KE OF Q/V MflTE/Q/fl COLLOID EZECTROZYZE 196 190050 B ITSELF' 51/7- SIMULT/QNEOUSLY COMPLETED I INVENTOR. flames/2T MuLLEe ATTORNEYS I Patented Mar. 15, 1938 UNITED STATES PATENT OFFICE] Appiication September 27, 1934, Serial No. 745,755 In Germany September 28, 1933 10 Claims.

The present invention relates to the productlon of aqueous emulsions having positively charged disperse phases containing waxes, fats and/or oil, such as may be utilized for the treatment and impregnation of textiles and other materials.

Positively charged emulsions of waxes, fats, oils and other water insoluble material, have many advantageous properties, particularly in regard to the treatment of materials for impregnation such as textiles, paper, leather and so forth.

In producing such positively charged emulsions it has been customary to first produce the negatively charged emulsion and to convert this negatively charged emulsion into the positive emulsion by certain types of electrolytes, particularly acids, polyvalent metallic salts and so forth.

In converting the charge on a disperse phase from a negative one to a positive one, however, many difficulties are encountered, particularly when the emulsion passes the isoelectric point. At this point the emulsion shows a strong tendency to break up and coagulate.

Further it was necessary to utilize two separate process steps for the production of the com pleted emulsion, namely the emulsification procedure and then the reverse charging operation.

It has now been found that positively charged aqueous emulsions may be most satisfactorily produced by a single operation when the three emulsion components, namely the water insoluble oily,

i'atty or Waxy material, the protective colloid and the positively charging electrolyte are permitted to first react together in the'homogenizing'apparatus and preferably in such conditions that they will be mixed together in the proportions in which they are to be utilized in the finally positively charged emulsion.

According to this process a Wax, fat or oil in liquid condition is mixed with an aqueous solution of a protective colloid such as glue and with a positively charging electrolyte such as formic acid, and/or aluminum formate. To give several examples of the process, to an emulsifier or a homogenizing machine there may be added simultaneously, but each by itself molten hard paraflin, a solution of glue and a solution of formic acid. About 120 parts by weight of parafiin are utilized for every parts by weight of glue dissolved in 100 parts by weight of water, and every 5 parts by Weight of 85% formic acid dissolved in 150 parts by weight of water.

In adding these materials to the homogenizing machine they are preferably fed gradually to the machine in the proportions in which they will appear in the finished emulsion.

In preparing the emulsion, the temperature of the paraffin as well as the solutions of glue and formic acid should be about 50 to C.

p In another example 20 parts by weight of dimethyl cellulose are permitted to soak and swell overnight in 250 parts by weight of Water having a temperature of 30 to 35 C. To this material is then added a solution of 5 parts by weight of gelatin in 50 parts of water which has been heated to 35 C. This mixture is then combined with 150 parts by weight of molten cocoa fat and 50 parts by weight of aluminum formate solution of 12.5 B.

These three solutions are all gradually poured simultaneously but each by itself into a mixing machine and a satisfactory emulsion will be formed and if desired it may be passed through a homogenizing machine.

The composition of the four final emulsions above prepared are respectively as follows:

Example I Percent Parafiin 28.2 Glue c 11.7 Formic acid (100%) 1.2 Water 58.9

Example II Percent Cocoa fat 21.9 Gelatin 0.75 Aluminum formate 0.45 Dimethyl cellulose 2. 9 Water 74.0

It has already been proposed to produce positively charged emulsions by mixing gradually in an emulsifying device, the water-insoluble substance to be emulsified with an aqueous solution of a protective colloid, for example, glue, and-of a positively-charging electrolyte for example a water-soluble aluminum salt. However, in this process the aluminum salt is present in the solutf'on even before the water-insoluble substance is emulsified with the glue, with the result that the glue is modified in respect to its physical and chemical properties.

Therefore, the emulsifying and stabilizing effect of the glue which is desirably present in the beginning of the emulsiilcation is disadvantageously aifected by such aluminum salt before the emulsification may be completed.

In the present process this disadvantage is iii eliminated since the aluminum salt or other posi-,

tively charging electrolyte comes into contact with the protective colloid only as the emulsion is prepared so that the glue canot be disadvantageously affected before emulsification of the water-insoluble material.

If the glue solution and aluminum salt solution are mixed and then emulsified with, for example, molten parafiin, the process of emulsification requiring say a number of hours, the glue will be disadvantageously modified before all the paraffin has been emulsified.

In the present process the glue used for emulsification is not exposed to action of aluminum salts for a long time, but is freshly used for preparation of the emulsion.

The accompanying drawing illustrates how the components are mixed simultaneously but each by itself.

It is to be understood, of course, that other water-insoluble materials may be used to form a disperse phase and that other reverse charging electrolytes may be utilized other than those specifically described above.

The protective colloids may be other than glue.

These emulsions may be employed'in connection with the impregnation and treatment of textiles, leather, and paper.

The present application is a continuation in part of the applications Serial Nos. 562,608, filed September 12, 1931;. 638,345 filed October 18, 1932 and 659,506, filed March 3, 1933.

What is claimed is:

1. A process of preparing a positively charged aqueous emulsion of oily, fatty, waxy and other water-insoluble materials directly from the constituents thereof by simultaneous intermixture and emulsification thereof, said process comprising mixing and substantially simultaneously emulsifying together an aqueous solution of an organic protective colloid, an aqueous solution of a positively charging electrolyte and a water- .insoluble material to form an emulsion, whereby the three components are poured simultaneously, but each by itself into a mixing machine, and in the proportions in which they are to be present in the final emulsion, said emulsion being formed before the components thereof have an opportunity to interact with one another in unemulsified condition.

2. A process of preparing a positively charged aqueous emulsion of oily, fatty, waxy and other water-insoluble materials directly from the constituents thereof by simultaneous intermixture and emulsification thereof, said process compris- 1 ing mixing and substantially simultaneously homogenizing together an aqueous solution of the organic protective colloid, an aqueous solution of the positively charging electrolyte and a water-insoluble material whereby the three components are poured simultaneously, but each by itself into the homogenizing machine and in the proportions in which said materials are to occur in the final emulsion, said emulsion being formed before the components thereof have an opportunity to interact with one another in unemulsifled condition.

3. A process of preparing a positively charged aqueous emulsion of oily, fatty, waxy and other water-insoluble materials directly from the constituents thereof by simultaneous intermixture and. emulsification thereof, said process consisting of emulsifying together a solution of glue, a solution of formic acid, and molten parafiin.

4. A continuous process of forming positively charged emulsions which comprises flowing togetherthree liquids, one being a liquid water insoluble material selected from the group consisting of oils, fats and waxes, the second being an aqueous solution of a protective protein colloid and the third being an acid solution containing in solution one of a group of compounds, said group consisting of readily water soluble inorganic and organic acids and acid salts, said three liquids being mixed together simultaneously to immediately form an emulsion, and then homogenizing the emulsion formed by combination of said liquids as soon as the liquids are, mixed.

5. A positively charged emulsion comprising glue, formic acid and paraflin, said glue, formic acid and paraflin having been emulsified together before substantial contact in unemulsified condition.

6. A process of forming positively charged emulsions which comprises combining and simultaneously emulsifying without permittingsubstantial contact or interreaction in unemulsified condition a high molecular weight water insoluble ester of a fatty acid and an aliphatic alcohol, a water soluble protein and a water soluble acid material.

- '7. A process of forming positively charged emulsions which comprises combining and simultaneously emulsifying without permitting substantial contact or interreaction in unemulsified condition a high molecular weight water insoluble hydrocarbon, glue and a readily soluble acid.

I 8. A process of forming positively charged emulsions which comprises combining and simultaneously emulsifying without permitting substantial contact or interreaction in unemulsified condition a high molecular weight water insoluble hydrocarbon, glue and formic acid.

9. A process of forming positively charged emulsions which comprises combining and simultaneously emulsifying without permitting substantial contact or interreaction in unemulsified condition a high molecular weight water insoluble cocoa fat, a water soluble protein and a water soluble aluminum salt. 1

10. A positively charged emulsion comprising cocoa fat, gelatin, aluminum formate and dimethyl cellulose, said materials having been emulsified together before substantial contact in unemulsified condition.v

' ADALBERT MULLER. 

